rift valley fever: could re-emerge in Egypt again?

The Rift Valley fever [RVF] is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus of the family of Bunyaviridae, genus Phlebovirus. RVF is an acute, febrile disease affecting humans and a wide range of animals. The virus is trans-mitted through the bites from mosquitoes and exposure to viremic blood, body fluids, or contact with tissues of infected animals or by inhaling natural virus aerosols, also possibly by consumption of infected unpasteurized milk. The RVF-virus replicate at the site introduction and in local lymphatic followed by viremia and spread to other organs as the liver and central nervous system, causing the hepatic necrosis and eosinophilia cytoplasmic degeneration. The main signs and symptoms are fever, headache, myalgia, arthralgia, photophobia, bradycardia, conjunctivitis and flushing face. Main complications include jaundice, hemorrhagic, meningoencephalitis and retinal lesions. Generally speaking, in the21[st] Century, the vector-borne infectious diseases, was accepted as the disaster issues with the considerable significant morbidity and mortality. These facts should be considered by the public health, veterinary and agricultural authorities

potential role of Rattus rattus in enzoonotic cycle of Rift Valley Fever in Egypt. 2 - Application of reverse transcriptase polymerase chain reaction [RT-PcR] in blood samples of Rattus rattus

A reverse transcriptase -polymerase chain reaction [RT-PCR] was applied to detect Rift Valley Fever Virus [RVF-V] in blood samples of Rattus rattus [R. rattus] collected from 3 different governorates of Egypt, Alexandria, Behira and Minia governorates [one hundred each]. Out of 300 blood samples 29 [9.67%] were positive for RVF-Virus by RT-PCR with higher percent in Behira governorate rural areas [16%], followed by Minia governorate rural areas [13.85%] while the lowest percent was in Alexandria governorate urban areas [0.00%]. The overall percent in rural areas were [13.5%] while it was only [2.0%] in urban areas. Our Study suggests that, this R.rattus play an important role in the maintenance cycle of RVF-V in rural areas of Egypt

Application of reverse transcriptase - polymerase chain reaction for detection of rift valley fever viral antigen from mosquito

A reverse transcriptase polymerase chain reaction [RT-PCR] was applied to detect rift valley fever virus [RVFV] in Culex pipiens mosquito pools collected from Alexandria and Behira governorates of Egypt [50 pools each]. All mosquito pools were subjected to double sandwich enzyme linked immunosorbent assay [ELISA] technique to detect RVF viral antigen. Out of all 100 mosquito pools, only 18 were positive by ELISA, 10 out of 50 pools were positive in Behira Governorate and 8 were positive in Alexandria Governorate. All positive samples [18], in addition to two negative samples [one was used as a negative control and the other was used as a positive control after the addition of 1.0 ml of 103 inactivated RVF virus] were subjected to RT-PCR. Out of these 18 positive samples by ELISA, only 7 were positive for RVF Virus by RT-PCR. These results gave the possibilities of the existence of other phleboviruses that cross react with RVF virus

Mutagenic effect of rift valley fever virus as measured by indication of chromosomal aberrations and formation of micronuclei in mice bone marrow cells

The mutagenic effect of Rift Valley fever [RVF] virus was tested in male mice bone marrow cells. Three virus titers were chosen [low [L], intermediate [IM] and high [H]]. These were 3, 300 and 3000 VP/dose, respectively. Mice were inoculated with each titer and samples were taken 24 and 48 hours later from bone marrow. An increase in chromosomal aberrations [structural and numerical] was observed in some treatments with RVF virus. The significant structural chromosomal aberrations are in the form of gape and centromeric attenuations, while the numerical aberration was endomitosis. All treatments showed a decrease in mitotic index [number of dividing nuclei per 300 cells], this decrease was highly significant. Although, the number of micronucleated PCE increased after inoculation with all treatments, the increase was below the significant level. Since there is no information available on the mutagenicity of RVF virus, more cytogenetic studies are suggested, the result of which could be compared with these results. This may throw some light on the mutagenic effect that could be produced by RVF virus